Method for ascertaining a parking area of a street section

ABSTRACT

A method for ascertaining a parking area of at least one street section includes providing information indicating a usable width of the street section, the usable width representing a drivable width of the street section between spaces for parked vehicles at the two lateral sides of a driving vehicle; the driving vehicle driving the street section and ascertaining lateral distances from objects using an ascertainment device situated in the driving vehicle; comparing the ascertained lateral distances to the usable width; and ascertaining the parking area by way of the comparison.

FIELD OF THE INVENTION

The present invention relates to a method for ascertaining a parkingarea of at least one street section. The present invention furtherrelates to a device for ascertaining a parking area of at least onestreet section.

BACKGROUND

Various methods are known in the related art for ascertaining distancesof a vehicle from objects with the aid of distance-based sensors (e.g.,ultrasonic sensors, radar sensors, video sensors, lidar sensors).

A transmission of parking space data to a server is known for examplefrom DE 10 2004 062 021 A1, DE 10 2009 028 024 A1 and DE 10 2008 028 550A1.

SUMMARY

An objective of the present invention is to provide an improved methodfor ascertaining a parking area of a street section.

According to an example embodiment, the objective is attained by amethod for ascertaining a parking area of at least one street sectionincluding the steps of: providing a usable width of a street section,the usable width representing a drivable width of the street sectionbetween parked vehicles; driving the street section using anascertaining vehicle and ascertaining lateral distances from objectsusing an ascertainment device situated in the ascertaining vehicle;comparing the ascertained lateral distances to the usable width; andascertaining the parking area by way of the comparison.

The method may be used advantageously especially for completingincomplete parking space maps. If the measured usable width (betweenvehicles at both sides of the driving vehicle) coincides with the known,i.e., expected, usable width, an inference is made that the parking areais occupied. Ultimately, this makes it possible to use parked vehiclesto detect parking areas, whereby known methods based exclusively ondetecting parking spaces are significantly improved.

On account of the information regarding the usable width of the streetsection, it is possible advantageously to ascertain parking areas and toprovide these for example in the form of a parking space map. Thisallows for parking areas to be learned quickly, as a result of which itbecomes possible to prepare a complete and current parking space mapusing a relatively small number of passes.

In an example, the method is further characterized by that, in the eventof a defined deviation of the ascertained lateral distances from theusable width, which initially indicates an apparent parking area, butwhich apparent parking area is determined because of a vehicle parked ina second row of the street section (within the usable width), theapparent parking area is discarded. It is thus possible to filter outdetected “false” parking areas so that these do not enter the parkingspace map.

In an example, the method is further characterized by that, in the eventof a defined deviation of the ascertained lateral distances from theusable width, an apparent parking area ascertained on the basis of avehicle of oncoming traffic is discarded. Even in the event of oncomingtraffic, it is thus possible to filter out a “false” parking areadetected on the basis of the detection mechanism, which is therefore notentered in the parking space map. Ultimately, a type of“deplausibilization of parking space” is thus provided, which isadvantageously functional even when the usable width is not representedbetween vehicles parked on the edges of the street.

In an example, the method further provides for a maximum usable width ofthe street section to have the following value: 2×the maximum range ofthe ascertainment device+width of the ascertaining vehicle. This makesit possible to take the ranges of different sensor technologies intoaccount such as e.g., ultrasound, radar, laser, etc. In the event thatthe sensor technology used does not reach the mentioned range,additional localization methods may be used, e.g., using GPS data.

In an example, the method further provides for a position of the vehicleto be detected in the event that a range of the ascertainment devicedoes not cover the entire usable width, the detected position beingcompared to the ascertained lateral distances. In this manner, theproper functionality of the method is ensured even when the usable widthof the street section exceeds the sensor range.

In an example, the method further provides for ascertaining objects, inparticular vehicles, from the ascertained distance values. Objects, inparticular vehicles, are thereby detected from the ascertaineddistances, which are determined from defined echoes of the ascertainmentdevice. Other objects, e.g., advertisement pillars, garbage containersetc., may also be detected, which do not enter the parking space map.

Ultimately, this makes it possible to prepare a parking area map quicklyand efficiently.

In an example, the method further provides for the method to be carriedout at least partly locally in the ascertaining vehicle and/or at leastpartly in a server facility. In this manner, an existing processingcapacity may be distributed or utilized in the best way possible.

In an example, the method further provides for the ascertained distancedata to be transmitted to the server facility in an automated fashion.This makes it possible to aggregate in the long term a great quantity ofhistorical data, which represent the conditions in a very current andaccurate fashion.

In an example, the method further provides for the method to be carriedout in real time while the street section is driven or just after thestreet section is driven in an evaluation phase. This makes it possibleadvantageously to implement different evaluation strategies.

In an example, the method further provides for the street section to bedriven in different directions of travel, the ascertainment data of thedrives in the different directions of travel being correlated. Drivingthe street section in opposite directions advantageously allows for aneven more precise ascertainment of the parking area.

In an example, the method is further characterized by that parking areasare ascertained for a defined length of the street section. This makesit possible to produce parking space maps for selectively chosen areas.

According to an example embodiment, the objective is attained by adevice for ascertaining a parking area of a street section, the deviceincluding an ascertaining vehicle equipped with an ascertainment device,it being possible to ascertain lateral distances using the ascertainmentdevice, a usable width of the street section being known to the device,and a parking area being ascertainable from a comparison of theascertained lateral distances with the usable width.

The present invention is described below in detail with additionalfeatures and advantages, with reference to several figures. For thispurpose, each and every of the features presented in any of thespecification, drawings, and claims form the subject matter of thepresent invention. The figures are specifically intended to illustratethe principles that are essential to an understanding of the presentinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic sketch for explaining a functional principle ofthe method, according to an example embodiment of the present invention.

FIG. 2 is a diagrammatic sketch for explaining an advantageousdevelopment of the method, according to an example embodiment of thepresent invention.

FIG. 3 is a diagrammatic sketch for explaining a deplausibilization ofan apparent parking area due to a vehicle in the second lane, accordingto an example embodiment of the present invention.

FIGS. 4 and 5 are diagrammatic sketches for explaining adeplausibilization of an apparent parking area as a result of oncomingtraffic, according to an example embodiment of the present invention.

FIG. 6 is a diagrammatic sketch for explaining a recognition of aparking area, according to an example embodiment of the presentinvention.

FIGS. 7 and 8 are diagrammatic sketches for explaining a sensor range,according to an example embodiment of the present invention.

FIG. 9 is a flowchart of a method according to an example embodiment ofthe present invention.

DETAILED DESCRIPTION

In the sense of the present invention, a so-called “usable width” or“drivable driving width” or “drivable driving lane” or “real streetwidth” of a street or a section of a street defines a physical width ofthe street from curb to curb minus a respective width of a parkedvehicle on each edge of the street. It is thus assumed that the usablewidth is defined only in those areas of the street that are bounded byparking areas. For this purpose, the usable width is ascertained by apre-filtering process, in which e.g., the walls of buildings are nottaken into account as limiting elements of the street section forascertaining the usable width.

Conventionally, to ascertain the usable width, specific reflectionpatterns of alternating vehicles and parking spaces are normally used.The ascertainment of the mentioned parking spaces is in this instancebound up with a detection of characteristic echo images, it beingnecessary, e.g., for there to exist respectively a sequence of [parkedvehicle—parking space] or [parking space—parked vehicle] in order todetect the parking space. This requires an extensive number of drivesthrough the street section, it being very difficult to ascertain orverify areas, which are subject to great parking pressure and which areconsequently very seldom or never free, as a parking area.

FIG. 1 shows a fundamental functional principle of method forascertaining a parking area of a street section, according to an exampleembodiment of the present invention. An ascertaining vehicle 10 isshown, which drives along a street section 1 in the direction of thearrow. On both edges of street section 1, parked vehicles are shown,which occupy parking areas 13 (covered by vehicles 11) of street section1. Ascertaining vehicle 10 includes an ascertainment device 12 fordetecting a distance from objects situated laterally with respect to thedirection of travel, ascertainment device 12 including an ultrasonicsensor, a radar sensor or another suitable sensor.

As already mentioned, ascertainment device 12 has advance informationregarding a usable width 3 of the street section 1, a manner ofascertaining the usable width 3 and a manner of providing the usablewidth 3 being ultimately of secondary importance for ascertainmentdevice 12. Ascertainment device 12 furthermore has information regardingthat street section 1 has parking areas 13 at least on one side.

When street section 1 is driven, an example embodiment of the presentinvention provides for the detection of distances from objects,preferably vehicles 11, situated laterally from ascertaining vehicle 10,and for comparing these with known usable width 3. In this manner, asmany lateral distances as possible are detected between ascertainingvehicle 10 and parked vehicles 11, at least one measurement beingperformed laterally essentially at a right angle on the left and on theright of ascertaining vehicle 10. The mentioned ascertainments areultimately available in the form of limit points 2 of usable width 3,which thus represent “scanning points” of usable width 3. Because oftolerance thresholds, usable width 3 is represented by an arithmeticaverage value of distances between limit points 2.

In the event that, as shown in FIG. 1, the measured distance within thescope of a defined tolerance threshold (due to measurement or parkinginaccuracies) essentially agrees with the previously known usable width3, an inference is made to the effect that parking areas 13 along streetsection 1 are occupied. In this manner, it is possible to prepare acomplete parking space map within a short time, since, unlike in therelated art, it is not necessary that there be unoccupied parking areas13 (“parking spaces”) in order to detect parking areas 13.

FIG. 2 shows a principle of an advantageous development of the method.In this instance, objects, preferably in the form of vehicles 11, areascertained or modeled from the measured lateral distance values by wayof a processing step, which is indicated by tangential limit lines 2 aon those vehicles 11 which ascertaining vehicle 10 has already passed.In this case as well, usable width 3 is compared to the distancesbetween ascertained vehicles 11, and from this it is possible to inferparking areas 13.

FIG. 3 indicates a principle of a deplausibilization of a “false parkingarea” 13 a, which is detected in a space behind a vehicle 11 a that isparked in a second row and which is discarded for the purpose ofpreparing the parking space map. To detect a free parking area 13,ascertainment device 12 requires at least one object before or afterfree parking space 13 in order to generate a signal transition. This canbe achieved when there is a clear difference between a currentlymeasured usable width 3 a between vehicle 11 a parked in the second rowand the opposite vehicle 11 and the previously known usable width 3. Inthis instance as well, there is thus a comparison between the currentlymeasured usable width 3 a and the previously known usable width 3,whereby a false parking space is discarded, tagged or otherwise markedas invalid and is thus not taken up into the parking space map.

As indicated in FIG. 4, this may be done analogously also in the case ofan individual vehicle of oncoming traffic, the individual vehicle ofoncoming traffic and the ascertaining vehicle 10 driving past each otherat a defined low relative speed (e.g., approximately 45 km/h). Thementioned relative speed can be determined or adapted in a simple mannerusing suitable software algorithms. In this case too, there is nodetection of a false parking area 13 a, which is thus discarded and doesnot enter into the parking space map.

FIG. 5 essentially corresponds to FIG. 4, a scenario being representedin this case with moving oncoming traffic, in which a larger spaceoccurs between two individual vehicles of the oncoming traffic, which isrecognized as a false parking area 13 a and is discarded ordeplausibilized for the purpose of producing the parking space map.

FIG. 6 shows a “positive comparison” between known usable width 3 andthe currently measured usable width 3 a, the currently measured usablewidth 3 a being greater than the known usable width 3, and for thisreason a parking area 13 being recognized or validated.

FIG. 7 shows a scenario, in which a range of ascertainment device 12 onthe left side of ascertaining vehicle 10 is not sufficient forascertaining the distances from vehicles 11. Using ascertainment device12, it is thus possible to ascertain only the limit points 2 to theright of ascertaining vehicle 10. In this case, it is possible to useadditionally a position detection device (e.g., a GPS position detectiondevice) in order to determine a position of ascertaining vehicle 10 thatis accurate to within the centimeter range, and to ascertain in thismanner distances from the laterally situated vehicles 11. The followingequation applies for the maximum setpoint range d_(max) of ascertainmentdevice 12: d_(max)=2×maximum sensor range+width of the ascertainingvehicle

If ascertainment device 12 is unable to reach the stated setpoint ranged_(max), then no comparison can be performed with the previously knownusable width 3, and the mentioned position detection device must be usedadditionally.

FIG. 8 indicates that a range of ascertainment device 12 is increasedwith the aid of another sensor technology in order thereby to be able toperform the lateral measurements. In this manner, as provided, it ispossible to ascertain the limit points 2 on both sides of ascertainingvehicle 10. Depending on the sensor technology utilized in ascertainmentdevice 12, a different sensor range of ascertainment device 12 may beutilized, whereby different usable widths 3 may be ascertained dependingon the utilized technology.

The mentioned ascertainments of the lateral distances with theascertainment of parking areas 13 and the deplausibilization of falseparking areas 13 a can be performed locally in ascertainment device 12and/or in a decentralized server facility (not shown). Real-timeprocessing can be provided or processing can be performed subsequent todrives along the street section. A communication device required forprocessing in the server facility for wired or wireless communication ofascertainment device 12 with the server facility is not shown.

The accuracy and reliability of the ascertainment of parking areas 13increases with the number of drives through the respective streetsection 1 since averaging is then performed with an increased number ofmeasured values.

Advantageously, the ascertainment of parking area 13 can already beperformed in ascertaining vehicle 10 itself, for example byascertainment device 12 or a control unit provided for this purpose.Alternatively or additionally, it is also conceivable that all acquireddata are transmitted via a radio-based communication device (e.g., basedon GSM, EDGE, UMTS, LTE, WLAN etc.) of the ascertaining vehicle 10 to aserver facility, the ascertainment of parking area 13 in this case beingperformed by the server facility, which is normally significantly morepowerful.

Preferably, there can be a provision to ascertain parking areas 13 overa freely definable street section 1.

Preferably, there can also be a provision to perform the describedmeasurements also in a second direction of travel of street section 1and to correlate or compare them with the measured values of the drivethrough street section 1 performed in the first direction of travel (notshown). In this manner, it is possible to improve further a data qualityof parking areas 13 or an accuracy of the parking space map producedfrom these.

The method can be implemented advantageously using different sensortechnologies, e.g., ultrasonic sensors or radar sensors, which makes itpossible to take economic aspects into account.

The method is preferably implemented as software, which facilitatesadapting and updating the method.

FIG. 9 shows a basic flowchart of an example embodiment of the method ofthe present invention. In a step 20, a usable width 3 of street section1 is provided, the usable width 3 representing a drivable width ofstreet section 1 between parked vehicles 11. In a step 21, streetsection 1 is driven by an ascertaining vehicle 10 and lateral distancesfrom objects are ascertained by an ascertainment device 12 situated inascertaining vehicle 10. In a step 22, the ascertained lateral distancesare compared to usable width 3. Parking area 13 is ascertained by way ofthe comparison in a step 23.

In summary, the present invention provides a method and a device forascertaining a parking area of a street section. A type of “data mining”is performed for this purpose, which while driving carries out acontinual comparison of an ascertained usable width with a previouslyknown usable width. Ultimately, this makes it possible to produceparking space maps of high quality in an efficient manner.Advantageously, for recognizing the parking areas, it is possible to usealso parking areas that are in an occupied state, and it is notnecessary for parking areas to be unoccupied in order to be detected.

Although the present invention was described above with reference tospecific example embodiments, one skilled in the art is also able toimplement specific embodiments that were not disclosed above or thatwere disclosed above only partially, without deviating from the essenceof the invention.

What is claimed is:
 1. A method for ascertaining a parking area of astreet section, the method comprising: driving the street section by anascertaining vehicle; ascertaining, by an ascertaining device in theascertaining vehicle, lateral distances from objects, the lateraldistances being ascertained during the driving; comparing, by processingcircuitry, the ascertained lateral distances to a predetermined usablewidth of the street section, the predetermined usable width representinga drivable width of the street section between parked vehicles; andascertaining, by the processing circuitry, the parking area based on thecomparison.
 2. The method of claim 1, wherein the method is performedaccording to an algorithm by which an apparent parking area ascertainedon the basis of a double-parked vehicle is discarded, based on adeviation in a predefined manner of the ascertained lateral distancesfrom the usable width.
 3. The method of claim 1, wherein the method isperformed according to an algorithm by which an apparent parking areaascertained on the basis of an on-coming vehicle is discarded, based ona deviation in a predefined manner of the ascertained lateral distancesfrom the usable width.
 4. The method of claim 1, wherein a maximum rangeof a total of the lateral distances which the ascertaining device canascertain is 2*a maximum range of the ascertainment device+a width ofthe ascertaining vehicle.
 5. The method of claim 4, wherein the methodfurther comprises, in an event that the maximum range does not cover theentire usable width, detecting a position of the ascertaining vehicle,and using the detected position.
 6. The method of claim 1, whereinobjects are ascertained from the ascertained lateral distances.
 7. Themethod of claim 6, wherein the objects are vehicles.
 8. The method ofclaim 1, wherein the processing circuitry is at least partly located inthe ascertaining vehicle.
 9. The method of claim 1, wherein theprocessing circuitry is at least partly located in a server remote fromthe ascertaining vehicle.
 10. The method of claim 1, wherein theascertaining of the parking area is carried out in real time while thestreet section is being driven.
 11. The method of claim 1, wherein theascertaining of the parking area is carried in an evaluation phase afterthe street section has been driven.
 12. A device for ascertaining aparking area of a street section, the device comprising: an ascertainingvehicle that includes an ascertainment device, wherein the ascertainingdevice includes (a) a sensor for ascertaining lateral distances fromobjects, the lateral distances being detected while the ascertainingvehicle is driving, and (b) circuitry using which: the ascertainedlateral distances are compared to a predetermined usable width of thestreet section, the predetermined usable width representing a drivablewidth of the street section between parked vehicles; and the parkingarea is ascertained based on the comparison.
 13. The device of claim 12,wherein the ascertaining vehicle includes a communication device fortransmitting data of the ascertainment device to a server facility forthe ascertainment of the parking area.
 14. The device of claim 12,wherein the sensor is an ultrasonic sensor or a radar sensor.
 15. Anon-transitory computer-readable medium on which are stored instructionsthat are executable by a computer processor and that, when executed bythe processor, cause the processor to perform a method for ascertaininga parking area of a street section, the method comprising: obtaining,which an ascertaining vehicle is driving the street section, lateraldistances from objects; comparing the ascertained lateral distances to apredetermined usable width of the street section, the predeterminedusable width representing a drivable width of the street section betweenparked vehicles; and ascertaining the parking area based on thecomparison.